Method for manufacturing hydrated magnesium carbonate

Abstract

Disclosed is a method for manufacturing hydrated magnesium carbonate. Designed to produce high-purity hydrated magnesium carbonate from a solution where calcium ions and magnesium ions coexist, the method can add value to the resources. Compared to conventional techniques, the method can be conducted in a simpler procedure and allows for the production of high purity magnesium oxide (MgO), thus bringing about an economical benefit.

What is claimed is: 
     
         1 . A method for manufacturing hydrated magnesium carbonate, comprising:
 preparing a material solution containing calcium and magnesium, and a carbonate solution;   mixing the material solution with the carbonate solution calcium while stirring to produce a first mixed solution, with concomitant precipitation of magnesium carbonate; and   mixing a hydroxide solution to the first mixed solution while stirring to give a produce a second mixed solution, with concomitant precipitation of hydrated magnesium carbonate (HMC).   
     
     
         2 . The method of  claim 1 , wherein the carbonate solution is used in such an amount that the magnesium of the material solution is mixed at a molar ratio of 1:0.6˜1:1.0 with carbonate ions. 
     
     
         3 . The method of  claim 2 , wherein the carbonate solution is a sodium carbonate (Na 2 CO 3 ) solution. 
     
     
         4 . The method of  claim 2 , wherein the hydroxide solution is used in such an amount that the magnesium of the material solution is mixed at a molar ratio of 1:0.1˜1:0.3 with hydroxide ions. 
     
     
         5 . The method of  claim 4 , wherein the hydroxide solution is a sodium hydroxide (NaOH) solution. 
     
     
         6 . The method of  claim 2 , wherein the second mixed solution is maintained to have a pH of 8 to 10. 
     
     
         7 . The method of  claim 6 , further comprising, after the production of the second mixed solution,
 filtering the second mixed solution to separate the precipitate;   washing the precipitate to remove impurities from the precipitate; and   drying the purified precipitate in an oven.   
     
     
         8 . The method of  claim 7 , wherein the hydrated magnesium carbonate (HMC) is selected from the group consisting of 4(MgCO 3 ).Mg(OH) 2 .4H 2 O, 4(MgCO 3 ).Mg(OH) 2 .5H 2 O, and 4(MgCO 3 ) .Mg(OH) 2 .8H 2 O. 
     
     
         9 . The method of  claim 7 , further comprising roasting the dried precipitate at 800 to 1,000° C. to afford highly pure magnesium oxide (MgO). 
     
     
         10 . A method for manufacturing hydrated magnesium carbonate, comprising:
 preparing a material solution containing calcium and magnesium, and a carbonate solution;   mixing the material solution with the carbonate solution calcium while stirring to precipitate calcium carbonate;   isolating the precipitated calcium carbonate;   mixing the remaining solution with a carbonate solution by stirring to produce a first mixed solution, with concomitant precipitation of magnesium carbonate; and   adding a hydroxide solution to the first mixed solution while stirring to produce a second mixed solution, with concomitant precipitation of hydrated magnesium carbonate (HMC).   
     
     
         11 . The method of  claim 10 , wherein the carbonate solution is used in such an amount that the magnesium of the material solution is mixed at a molar ratio of 1:0.6˜1:1.0 with carbonate ions. 
     
     
         12 . The method of  claim 11 , wherein the carbonate solution is a sodium carbonate (Na 2 CO 3 ) solution.